Ricerc@Sapienza

The rate of multiple pregnancies is showing a significant increase in Western countries. Twin gestations should be considered a high-risk condition because they are responsible for a disproportionate amount of overall perinatal morbidity and mortality due to fetal and maternal complications often related to impaired utero-placental function.
This is an observational study of uterine artery (UtA) Doppler velocimetry in women with dichorionic (DC) and monochorionic (MC) twin pregnancies.
We aim to discover if transabdominal UtA pulsatility index (PI) differs between MC diamniotic and DC twins and if it is useful to predict pregnancy complications compared to singletons .
Our secondary outcome is to create a reference chart of normal range for UtA Doppler parameters (pulsatility index and resistence index) in twin pregnancies for clinical use. We assume to include uncomplicated twin pregnancies, available for full pregnancy follow-up. Uterine Doppler velocimetry will be performed at first, second and third trimester and compared for demographic characteristics, mean UtA PI, presence of notch, development of preeclampsia, fetal growth restriction (FGR), placental abruption, intrauterine fetal death and preterm delivery.
Sensitivity, specificity, positive predictive value, negative predictive value, and likelihood ratio will be calculated for mean PI >95th percentile, presence of notch, and presence of either elevated PI or notch.
UtA measurements will be performed by color and pulsed Doppler imaging. The uterine artery PI and RI will be calculated as a mean of both sides. Reference ranges will be constructed related on gestational age.
Our purpose is to give to the sonographers updated information and a high sensitive tool for identifying properly low- and high-risk groups, and to better manage twin pregnancies.